The present invention relates to a control device for a ballistic unit, such as a missile of the type including a motor that generates a propelling gas and which also includes a motor nozzle. The control device may comprise at least one spoiler which can be moved in and out of the flow of propelling gas at the exhaust opening of the nozzle.
By moving, the spoiler into the jet of propelling gas flowing from the nozzle the gas flow from the nozzle is influenced, resulting in deflection of the thrust vector of the jet of propelling gas. This is a known method of achieving a desired control moment in a missile or the like. It is known to arrange the interfering body or spoiler blade in question so that it travels at right angles to the centre axis of the motor nozzle at the exhaust opening of the nozzle. It is also known to have the interfering body supported on a rotatable shaft which is parallel to or at right angles to the centre axis of the nozzle, which allows the interfering body to be moved into or out of the gas flow path with comparatively small movements. The members (servos, electromagnets, etc.) required for the operation of the interfering body or the spoiler can therefore be made simple, light and relatively inexpensive.
However, a disadvantage of know arrangements is that the angle of deflection is limited to not more than 15.degree. and the effective thrust of the propelling motor is considerably reduced, particularly at large angles of deflection (the maximum deflection angles). These disadvantages result from the interfering body giving rise to two counteracting moments around the missiles centre of gravity.